docs: def differential_pressure_meter_dP(D, D2, P1, P2, C=None, 
                                     meter_type=ISO_5167_ORIFICE):
      r'''Calculates either the non-recoverable pressure drop of a differential
      pressure flow meter based on the geometry of the meter, measured pressures 
      of the meter, and for most models the meter discharge coefficient.
      
      Parameters
      ----------
      D : float
          Upstream internal pipe diameter, [m]
      D2 : float
          Diameter of orifice, or venturi meter orifice, or flow tube orifice,
          or cone meter end diameter, or wedge meter fluid flow height, [m]
      P1 : float
          Static pressure of fluid upstream of differential pressure meter at the
          cross-section of the pressure tap, [Pa]
      P2 : float
          Static pressure of fluid downstream of differential pressure meter or 
          at the prescribed location (varies by type of meter) [Pa]
      C : float, optional
          Coefficient of discharge (used only in orifice plates, and venturi
          nozzles), [-]
      meter_type : str, optional
          One of ('ISO 5167 orifice', 'long radius nozzle', 'ISA 1932 nozzle', 
          'as cast convergent venturi tube', 
          'machined convergent venturi tube', 
          'rough welded convergent venturi tube', 'cone meter', 'cone meter'), 
          [-]
          
      Returns
      -------
      dP : float
          Non-recoverable pressure drop of the differential pressure flow
          meter, [Pa]
  
      Notes
      -----
      See the appropriate functions for the documentation for the formulas and
      references used in each method.
      
      Wedge meters, and venturi nozzles do not have standard formulas available
      for pressure drop computation.
          
      Examples
      --------
      >>> differential_pressure_meter_dP(D=0.07366, D2=0.05, P1=200000.0, 
      ... P2=183000.0, meter_type='as cast convergent venturi tube')
      1788.5717754177406
      '''
      if meter_type == ISO_5167_ORIFICE:
          dP = dP_orifice(D=D, Do=D2, P1=P1, P2=P2, C=C)
  
      elif meter_type == LONG_RADIUS_NOZZLE:
          dP = dP_orifice(D=D, Do=D2, P1=P1, P2=P2, C=C)
      elif meter_type == ISA_1932_NOZZLE:
          dP = dP_orifice(D=D, Do=D2, P1=P1, P2=P2, C=C)
      elif meter_type == VENTURI_NOZZLE:
          raise Exception(NotImplemented)
      
      elif meter_type == AS_CAST_VENTURI_TUBE:
          dP = dP_venturi_tube(D=D, Do=D2, P1=P1, P2=P2)
      elif meter_type == MACHINED_CONVERGENT_VENTURI_TUBE:
          dP = dP_venturi_tube(D=D, Do=D2, P1=P1, P2=P2)
      elif meter_type == ROUGH_WELDED_CONVERGENT_VENTURI_TUBE:
          dP = dP_venturi_tube(D=D, Do=D2, P1=P1, P2=P2)
          
      elif meter_type == CONE_METER:
          dP = dP_cone_meter(D=D, Dc=D2, P1=P1, P2=P2)
      elif meter_type == WEDGE_METER:
          dP = dP_wedge_meter(D=D, H=D2, P1=P1, P2=P2)
      return dP